/*
* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.text.BreakIterator;
import java.text.CharacterIterator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
public class MirroredBreakIterator extends BreakIterator {
private final List<Integer> boundaries;
private int charIndex;
private int boundaryIndex;
MirroredBreakIterator(BreakIterator bi) {
List<Integer> b = new ArrayList<Integer>();
int i = bi.first();
charIndex = i;
for (; i != DONE; i = bi.next()) {
b.add(i);
}
boundaries = Collections.unmodifiableList(b);
}
@Override
public Object clone() {
try {
return super.clone();
} catch (Exception e) {
throw new RuntimeException("clone failed", e);
}
}
@Override
public int first() {
return changeIndices(0);
}
@Override
public int last() {
return changeIndices(boundaries.size() - 1);
}
@Override
public int next(int n) {
if (n == 0) {
return current();
}
int newBoundary = boundaryIndex + n;
if (newBoundary < 0) {
first();
return DONE;
}
if (newBoundary > lastBoundary()) {
last();
return DONE;
}
return changeIndices(newBoundary);
}
@Override
public int next() {
if (boundaryIndex == lastBoundary()) {
return DONE;
}
return changeIndices(boundaryIndex + 1);
}
@Override
public int previous() {
if (boundaryIndex == 0) {
return DONE;
}
return changeIndices(boundaryIndex - 1);
}
@Override
public int following(int offset) {
validateOffset(offset);
for (int b = 0; b <= lastBoundary(); b++) {
int i = boundaries.get(b);
if (i > offset) {
return changeIndices(i, b);
}
}
return DONE;
}
@Override
public int preceding(int offset) {
validateOffset(offset);
for (int b = lastBoundary(); b >= 0; b--) {
int i = boundaries.get(b);
if (i < offset) {
return changeIndices(i, b);
}
}
return DONE;
}
@Override
public boolean isBoundary(int offset) {
// Call the default impelementation in BreakIterator
return super.isBoundary(offset);
}
@Override
public int current() {
return charIndex;
}
@Override
public CharacterIterator getText() {
throw new UnsupportedOperationException();
}
@Override
public void setText(CharacterIterator newText) {
throw new UnsupportedOperationException();
}
private int lastBoundary() {
return boundaries.size() - 1;
}
private int changeIndices(int newCharIndex, int newBoundary) {
boundaryIndex = newBoundary;
return charIndex = newCharIndex;
}
private int changeIndices(int newBoundary) {
try {
return changeIndices(boundaries.get(newBoundary), newBoundary);
} catch (IndexOutOfBoundsException e) {
throw new IllegalArgumentException(e);
}
}
private void validateOffset(int offset) {
if (offset < boundaries.get(0) || offset > boundaries.get(lastBoundary())) {
throw new IllegalArgumentException();
}
}
}